(19)

(11)

EP 1 633 682 A1

(12)

(43) Date of publication: 15.03.2006 Bulletin 2006/11 (21) Application number: 04726203.5 (22) Date of filing: 07.04.2004

(51) International Patent Classification (IPC):  C02F 3/00(2000.01) F01D 17/14(1968.09) (86) International application number: PCT/GB2004/001532 (87) International publication number: WO 2004/108610 (16.12.2004 Gazette 2004/51)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR (30) Priority: 07.06.2003 GB 0313143 (71) Applicant: The BOC Group plc Windlesham Surrey GU20 6HJ (GB)	(72) Inventor: GRADWELL, Kevan Lostock, Bolton BL6 4EQ (GB) (74) Representative: Booth, Andrew Steven  The BOC Group plc, Chertsey Road Windlesham, Surrey GU20 6HJ Windlesham, Surrey GU20 6HJ (GB)